Definition 1 ([1]}, [2]}) 
A mechanism \({\mathsf {K}}:{\mathcal {X}}\rightarrow {\mathcal {P}}({\mathcal {Z}})\)  is \((\varepsilon , \delta )\) -LDP for \(\varepsilon \ge 0\)  and \(\delta \in [0,1]\)  if
\(\sup _{x, x^{\prime }\in {\mathcal {X}}} \sup _{A\subset {\mathcal {Z}}}~\left[{\mathsf {K}}(A|x)-e^\varepsilon {\mathsf {K}}(A|x^{\prime })\right] \le \delta .\) 
